Residents of the the Kensington, the luxury apartment complex in Downtown Crossing, may have been alarmed when Percy Fortini-Wright showed up with cans of spray paint. Not anymore. Fortini-Wright, who was a graffiti artist in his youth, put his considerable talents to use to create a new mural at The Kensington. The work, titled “Paramount,” pays homage to the late, great Muhammad Ali as well as to the Paramount Theatre, which is located a few doors away.